The i-unit is a hierarchically organized information structure, in which each level consists of a number of subunits, all identically organized. The number of subunits in a level is called its length. Units eventually occur that cannot be decomposed further. These are called base-units and are some unit of information-e.g., the bit or the character. Thus, if the lengths are L1, L2, . . . , Ln and the base unit is the bit, then the total amount of information (the content of the i-unit) is L1 x L2 x . . . x Ln bits and the number of levels is n. The i-unit may be likened to an n-dimensional rectangular volume of information (except that the "dimensions"¾
the lengths¾
occur in a fixed order).

COMMENT

Almost all information in computer systems is organized in terms of i-units¾
e.g., a memory consists of a number of words, each of a number of characters, each of a number of bits. More exotic data structures are invariably encoded into i-units and are not reflected in the hardware.